CVE-2020-25595 Privilege escalation in n/a
A malicious guest with passed-through PCI devices can crash the Xen hypervisor or potentially escalate privileges due to unsanitized register data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-25595?
CVE-2020-25595 is a high-severity vulnerability in Debian Debian Linux, published on 23 Sep 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An issue was discovered in Xen through 4.14.x. The PCI passthrough code improperly uses register data. Code paths in Xen's MSI handling have been identified that act on unsanitized values read back from device hardware registers. While devices strictly compliant with PCI specifications shouldn't be able to affect these registers, experience shows that it's very common for devices to have out-of-spec "backdoor" operations that can affect the result of these reads. A not fully trusted guest may be able to crash Xen, leading to a Denial of Service (DoS) for the entire system. Privilege escalation and information leaks cannot be excluded. All versions of Xen supporting PCI passthrough are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only guests with passed through PCI devices may be able to leverage the vulnerability. Only systems passing through devices with out-of-spec ("backdoor") functionality can cause issues. Experience shows that such out-of-spec functionality is common; unless you have reason to believe that your device does not have such functionality, it's better to assume that it does.
Weakness: CWE-269
Which versions are affected by CVE-2020-25595?
It affects 4 products.
Products include Debian Debian Linux, Fedoraproject Fedora, Opensuse Leap, Xen Xen.
How do I fix CVE-2020-25595?
Apply the vendor's patch.
Is CVE-2020-25595 being exploited?
There is no known exploitation of CVE-2020-25595 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2020-25595, DEBIAN-CVE-2020-25595, GHSA-gx32-9whp-v6gp, UBUNTU-CVE-2020-25595.